Preparation of roadways, building sites, embankments and other surfaces often requires compaction to produce desired material properties. To facilitate material compaction, compactors (also referred to as compacting machines) are often employed to compact soil, gravel, asphalt, and other materials. Compactors may include, for example, a rotating drum having one or more rotatable drum assemblies which roll over the material to be compacted. The rotating drum may be a static roller system in which the weight of the compactor and the drum produces the compaction. Some compactors also include a vibratory mechanism which provides a compaction effort to enhance the compaction process, generally, based on the characteristics of the material to be compacted and stage of compaction operation.
Compaction operation generally includes driving one or more compactors over a work area multiple times until it is compacted to target. Material being compacted is normally initially soft and of low density before compaction begins. After each pass, the level of compaction of the material incrementally increases and therefore, the subsequent passes should be performed with a different compaction effort. Usually, this effect is achieved by using two or more distinct compactors in series with each one of the compactors set at a different compaction effort.
Current approaches for deciding and changing the setting of the vibratory mechanism rely mostly upon operator judgment and perception, which require substantial operator training and preparation time. These approaches have the potential for human error and tend to be inconsistent in quality. Accordingly, when constructing long roads and highways, a significant number of pavement and rolling deficiencies appear. These deficiencies tend to increase construction time and cost.
U.S. Pat. No. 6,236,923 (hereinafter referred to as “the '923 patent”) describes a method and apparatus for controlling the inflation pressure on a pneumatic compactor. The '923 patent describes that the method and apparatus includes means for dynamically determining a level of density of a material to be compacted, a control system for determining a desired inflation pressure as a function of the density, and an inflation pressure system for adjusting the inflation pressure in response to the desired inflation pressure. In one example, the '923 patent describes that the control system determines the level of density of material as a function of the number of passes of the pneumatic compactor over a compaction area.